1. Field of the Invention
The present invention generally relates to methods for cleaning soft contact lenses and, more particularly, is concerned with a mechanical means for removing the various undesirable build-ups on disposable soft contact lenses surfaces which limit their usable life.
2. Description of the Prior Art
Devices for cleaning contact lens have been described in the prior art for removing build-ups, which can be protein or bacterial, which eventually occur on the lens surface which makes the lens uncomfortable to the wearer and at this point the lenses are generally discarded in favor of a new pair of lenses. However, none of the prior art devices disclose the unique features of the present invention.
The device in this invention forestalls these build-ups appreciably if not totally in many cases, thus extending the wearable life of disposable soft lenses.
In U.S. Pat. No. 4,965,904 dated Oct. 30, 1990, Tanaka, et al., disclosed a contact lens cleaning device comprising a ball, a vessel formed with a recessed chamber for housing the lens and the ball, and a vibrator for vibrating the vessel. The chamber has a bottom concave surface so curved that the lens is mounted in fact-to-face contact thereon. After the lens is sandwiched between the bottom concave surface of the chamber, the ball is cleaned when the vessel is vibrated by the vibrator.
In U.S. Pat. No. 4,957,128, dated Sep. 18, 1990, Chen disclosed a contact lens cleaner which includes a base, a vibrating plate mounted swingably on the base, a container mounted removably on the vibrating plate so as to receive an amount of a cleaning liquid and a contact lens therein, a motor disposed on the base so as to swing the vibrating plate, a cam member mounted rotatably on the base and having a cam surface which is engaged with the free end of the vibrating plate, and a resilient element biasing the free end of the vibrating plate toward the cam member. When the motor is started so as to rotate the cam member, the cam surface of the cam member pushes the free end of the vibrating plate to move in one direction, while the resilient element moves the free end of the vibrating plate in the opposite direction to engage with the cam surface of the cam member, so as to swing the vibrating plate, thereby rinsing the contact lens with the cleaning liquid.
In U.S. Pat. No. 4,697,605, dated Oct. 6, 1987, Yung disclosed a contact lens cleaning and disinfecting apparatus with a cavity in which a contact lens is to be cleaned by an aqueous non-chemosterilant liquid such as a saline solution. An ultra-sonic transducer applies vibrations to the cavity. The oscillator driving the transducer includes a transformer feedback circuit using one or more cores of high magnetic permeability and low core loss to give a stable resonant frequency. A timer may be driven from this resonant frequency. In one embodiment the cavity and the sealing cap may be removable together with the transducer from the rest of the housing of the apparatus so that lenses can be transported conveniently after cleaning and before use. According to another embodiment the waste heat from power transistors can be used to heat the cleaning liquid in the cavity.
In U.S. Pat. No. 4,607,652, dated Aug. 26, 1986, Yung disclosed a contact lens cleansing apparatus which comprises at least one cavity for containing a contact lens together with cleansing a liquid. An ultrasonic transducer supplies ultrasonic frequency mechanical vibrations to the liquid and lens contained in the cavity. Oscillating means for driving ultrasonic transducer at a substantially stable resonant frequency includes a dual ferrite core transformer feedback circuit which minimizes energy consumption. There is also a timer whose operation is controlled from the oscillating means. Simultaneous cleaning and sterilizing of a contact lens is achieved.
In U.S. Pat. No. 5,144,144, dated Sep. 1, 1992, Borovsky disclosed a contact lens cleaning and disinfecting system which is formed as a compact unit with an upper housing portion containing a UV lamp and a lower base portion containing a cleaning/disinfecting chamber which is filled with saline solution, a lens holder, a turbulence mechanism for inducing turbulence in the fluid, and an electronic control unit for operating the UV lamp and the turbulence mechanism in a single cleaning/disinfecting cycle of comparatively short duration. The lens holder has a pair of lower lens holder portions for the lenses and an upper bracket for shading the lenses form direct UV radiation. The turbulence mechanism is a magnetic pedal, tethered on the end of a flexible spring, which is driven by a magnetic flux generator to create a whirlpool in the fluid which swirls in and around the lens holder portion. Particles, films and other deposits dislodged from the lenses are carried by the whirlpool above the upper bracket of the lens holder where they are disinfected by the UV radiation. The pedal is driven in oscillation in a sub-sonic range of about 50-120 cyc/-sec. An electrical contact interlock between the upper housing and the lower base prevent accidental operation and irradiation by the UV lamp. The whirlpool turbulence cleans deposits form the lenses, thereby avoiding the need for manual scrubbing and detergent chemicals. The UV radiation disinfects the dislodged deposits and fluid quickly, without heating, and without the need for preservatives and disinfectant chemicals.
While these devices for cleaning contact lens may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described.